RESUMO
The nutcracker phenomenon, also known as left renal vein entrapment, occurs when there is extrinsic compression of the left renal vein, most often between the abdominal aorta and the superior mesenteric artery. Nutcracker syndrome refers to the constellation of clinical symptoms that may arise from the nutcracker phenomenon, typically inclusive of haematuria, flank/pelvic pain, orthostatic proteinuria and (in male patients) varicocele. We provide a short review of the nutcracker syndrome including various diagnostic and therapeutic modalities. We utilise our own experience with a patient as a case study and highlight the modern management option of endovascular stenting.
RESUMO
Margin status is one of the most important prognostic factors in oral cancers. Intraoperative frozen section (FS) can be performed to ensure a margin-negative resection, however the method of FS assessment is debatable. The aim of this study was to compare the defect-driven (DDA) versus specimen-driven (SDA) approach for intraoperative assessment of tumour margins in oral cancer resections and their impact on loco-regional recurrence and survival. The primary study endpoint was margin status determined from the final histopathological examination report. Secondary endpoints were disease recurrence and survival. This retrospective cohort study compared the two methods of FS in terms of their performance and survival outcomes. All oral squamous cell carcinoma patients who underwent surgery as the primary treatment from January 2018 to February 2019 were included. The involved margin rate was slightly lower with SDA than DDA (7.5% vs 11.8%), however the difference was not statistically significant. The recurrence rate was higher with DDA (19/51, 37.2%) than SDA (14/53, 26.4%), although this was not statistically significant. Local recurrence-free survival (DDA 62% vs SDA 75%; P = 0.653) and overall survival (DDA 76% vs SDA 78%; P = 0.300) at 18 months of follow-up were comparable. There was no significant difference in sensitivity or specificity of intraoperative FS for margin assessment between SDA and DDA. The type of intraoperative FS technique used did not affect loco-regional recurrence or overall survival.
Assuntos
Carcinoma de Células Escamosas , Neoplasias Bucais , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/patologia , Secções Congeladas , Humanos , Margens de Excisão , Neoplasias Bucais/mortalidade , Neoplasias Bucais/patologia , Recidiva Local de Neoplasia/patologia , Estudos Retrospectivos , Taxa de SobrevidaRESUMO
We report time-of-flight neutron spectroscopy and neutron and x-ray diffraction studies of the 5d^{2} double perovskite magnets, Ba_{2}MOsO_{6} (M=Zn,Mg,Ca). These materials host antiferromagnetically coupled 5d^{2} Os^{6+} ions decorating a face-centered cubic (fcc) lattice and are found to remain cubic down to the lowest temperatures. They all exhibit thermodynamic anomalies consistent with a single phase transition at a temperature T^{*}, and a gapped magnetic excitation spectrum with spectral weight concentrated at wave vectors typical of type-I antiferromagnetic orders. However, while muon spin resonance experiments show clear evidence for time-reversal symmetry breaking below T^{*}, we observe no corresponding magnetic Bragg scattering signal. These results are shown to be consistent with ferro-octupolar symmetry breaking below T^{*}, and are discussed in the context of other 5d double perovskite magnets and theories of exotic orders driven by multipolar interactions.
RESUMO
Objectives: To establish normative Hand Grip Strength (HGS) data for Trinidad and Tobago and to assess factors that may influence hand grip strength within this population. Design and Methodology: A cross sectional study of participants between the ages of 18-80 years was conducted at five distinct geographic regions in Trinidad and Tobago. Demographic data was collected including hand dominance. HGS was measured using a Jamar dynamometer. Descriptive statistics were performed for all direct measurements and Pearson's correlation coefficient used to analyze the relationship between variables. All statistical analysis was performed using the Statistical Package for Social Sciences (SPSS v20) p-value < 0.05 was considered significant. Results: A total of 1354 participants took part in the study, with 121 exclusions leaving 1233 for analysis. There were 561 males (45.5%) and 672 females (54.5%). The mean age of the participants was 42.5 years (SD +/-15.5) and mean body mass index (kg/m2) 27.3 (SD +/- 6.0). The overall mean HGS for our sample was 28.4 kgs. (SD +/- 2.9) with males having a higher overall HGS compared with females. Conclusions: This study presents previously unreported normative data on HGS in a Trinidad and Tobago population. This data will allow for a more objective evaluation of hand function in patients following injury and has implications for the assessment of disability in workmen's compensation.
Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Força da Mão , Trinidad e TobagoRESUMO
Objectives: To investigate the epidemiology, management and predictors of mortality in severe sepsis. Design and Methodology: Prospective observational study in 4 Trinidadian Intensive Care Units (ICU) over a one year period August 2017-August 2018. Physiologic and treatment data was collected on admission to ICU and patients were followed up until ICU discharge and then at 28 days to determine mortality. Results: 163 patients fit the criteria for severe sepsis and were enrolled. Twenty-eight day and ICU mortality rate were 42% (68) and 34 % (56) respectively. Case distribution by the various hospitals were San Fernando General Hospital 62% (101), Port of Spain General Hospital 16% (26), Eric Williams Medical Sciences Complex 12.3% (20) and Sangre Grande Hospital 9.8% (16). The most common source of sepsis was pulmonary (54%) followed by abdominal (17%) and urological sepsis (14%). Acute Kidney Injury (AKI) was present in 71% (115) patients and 43% (46) of patients with stage 2 and above AKI received Renal Replacement Therapy (RRT) in the ICU. In the regression model, the only factors that were found to predict both 28 day and ICU mortality were stage 2 AKI [OR 6.2 (95% CI 1.7- 23.1, p = .007)], stage 3 AKI [OR 7.2 (95% CI, 2.1-24.0, p=.001)] , mean arterial pressure of < 60mmHg in the first 24 hours [OR 10.8 (95% CI 1.7-68.1, p= .001)], presence of either moderate-severe Acute Respiratory Distress Syndrome [OR 4.1 (95% CI 1.8 9.2, p = .002)] and Acute Physiology, Age, Chronic Health Evaluation (APACHE) II score [OR 1.08 (95% CI, 1.0-1.2, p=.039)]. Conclusion: Severe sepsis is associated with a high hospital mortality rate and this sepsis burden varies according to region. Limited access to RRT remains a problem in certain centers.
Assuntos
Humanos , Sepse , Choque Séptico , Trinidad e Tobago , EpidemiologiaRESUMO
OBJECTIVES: To compare combined conventional Freer medialisation and controlled synechiae, performed for middle meatal access (during the initial steps of functional endoscopic sinus surgery) and post-operative middle turbinate medialisation, with basal lamella relaxing incision, the latter of which is a single step for achieving both middle meatal access and post-operative medialisation. The study also compared the effects of controlled synechiae and basal lamella relaxing incision on post-operative olfaction. METHOD: A randomised prospective study was performed on 52 nasal cavity sides (32 patients). Only basal lamella relaxing incision was performed in one group, and both conventional medialisation and controlled synechiae were performed in the other. Intra-operative and post-operative photography was used to measure the middle meatal area. A pocket smell test was used to assess olfaction. RESULTS: There were no significant differences in operative middle meatal access and post-operative medialisation of the middle turbinate. Post-operative olfaction was affected more in the combined conventional medialisation and controlled synechiae group, compared to the basal lamella relaxing incision group, but this finding was not statistically significant. CONCLUSION: Basal lamella relaxing incision is an effective single-step technique for achieving adequate middle meatal access and post-operative medialisation, with no significant effect on olfaction.
Assuntos
Endoscopia/métodos , Cavidade Nasal/cirurgia , Procedimentos Cirúrgicos Nasais/métodos , Aderências Teciduais/cirurgia , Conchas Nasais/cirurgia , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Período Pós-Operatório , Estudos Prospectivos , Olfato , Ferida Cirúrgica , Resultado do Tratamento , Adulto JovemRESUMO
We describe outcomes after allogeneic hematopoietic cell transplantation (HCT) for mycosis fungoides and Sezary syndrome (MF/SS). Outcomes of 129 subjects with MF/SS reported to the Center for the International Blood and Marrow Transplant from 2000-2009. Median time from diagnosis to transplant was 30 (4-206) months and most subjects were with multiply relapsed/ refractory disease. The majority (64%) received non-myeloablative conditioning (NST) or reduced intensity conditioning (RIC). NST/RIC recipients were older in age compared with myeloablative recipients (median age 51 vs 44 years, P=0.005) and transplanted in recent years. Non-relapse mortality (NRM) at 1 and 5 years was 19% (95% confidence interval (CI) 12-27%) and 22% (95% CI 15-31%), respectively. Risk of disease progression was 50% (95% CI 41-60%) at 1 year and 61% (95% CI 50-71%) at 5 years. PFS at 1 and 5 years was 31% (95% CI 22-40%) and 17% (95% CI 9-26%), respectively. OS at 1 and 5 years was 54% (95% CI 45-63%) and 32% (95% CI 22-44%), respectively. Allogeneic HCT in MF/SS results in 5-year survival in approximately one-third of patients and of those, half remain disease-free.
Assuntos
Transplante de Células-Tronco Hematopoéticas , Micose Fungoide , Síndrome de Sézary , Condicionamento Pré-Transplante , Adulto , Fatores Etários , Idoso , Aloenxertos , Intervalo Livre de Doença , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Micose Fungoide/mortalidade , Micose Fungoide/terapia , Estudos Retrospectivos , Fatores de Risco , Síndrome de Sézary/mortalidade , Síndrome de Sézary/terapia , Taxa de SobrevidaRESUMO
OBJECTIVE: To describe the characteristic presentation of exertional leg pain in athletes and to discuss the diagnostic options and surgical management of exertional anterior compartment syndrome of the leg in this group of patients. METHODS: Data from a series of athletes presenting with exertional leg pain were analysed and categorized according to aetiology. RESULTS: Sixty-six athletes presenting with exertional leg pain in 102 limbs were analysed. Sixteen patients in a first group of 20 patients with a provisional diagnosis of exertional anterior compartment syndrome of the leg underwent a closed fasciotomy with complete resolution of symptoms. A second group of 42 patients were diagnosed as medial tibial stress syndrome and a third group of four patients had confirmed stress fracture of the tibia. CONCLUSION: Exertional leg pain is a common presenting complaint of athletes to sports physicians and physiotherapists. Careful analysis can lead to an accurate diagnosis and commencement of effective treatment. Exertional anterior compartment syndrome can be successfully treated utilizing a closed fasciotomy with a rapid return to sport.
OBJETIVO: Describir las manifestaciones características del dolor en la pierna que presentan los atletas, y discutir las opciones de diagnósticos y tratamiento quirúrgico del síndrome compartimental de la pierna en este grupo de pacientes. MÉTODOS: Los datos de una serie de atletas con dolor en la pierna debido al esfuerzo excesivo en los ejercicios, fueron analizados y categorizados según la etiología. RESULTADOS: Sesenta y seis atletas con dolor de piernas debido al esfuerzo excesivo en 102 miembros fueron analizados. Dieciséis pacientes en un primer grupo de 20 pacientes con un diagnóstico provisional de síndrome compartimental anterior de la pierna por esfuerzo experimentaron fasciotomía cerrada con resolución completa de los síntomas. Un segundo grupo de 42 pacientes fueron diagnosticados con síndrome de estrés medial de la tibia, y a un tercer grupo de cuatro pacientes se le confirmó fractura por estrés o sobrecarga de la tibia. CONCLUSIÓN: El dolor de la pierna por esfuerzo en los ejercicios es una queja común con las que los acuden a los médicos y fisioterapeutas de la medicina deportiva. Un análisis cuidadoso puede conducir a un diagnóstico preciso y al comienzo de un tratamiento eficaz. El síndrome compartimental anterior por esfuerzo puede tratarse con éxito utilizando una fasciotomía cerrada que permita un rápido retorno a la actividad deportiva.
Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto , Adulto Jovem , Traumatismos em Atletas , Síndrome do Compartimento Anterior/cirurgia , Fraturas da Tíbia/diagnóstico , Fraturas da Tíbia/terapia , Fraturas de Estresse/diagnóstico , Fraturas de Estresse/terapia , Esforço Físico , Fasciotomia , Síndrome do Compartimento Anterior/diagnóstico , Síndrome do Compartimento Anterior/etiologiaRESUMO
OBJECTIVE: To describe the characteristic presentation of exertional leg pain in athletes and to discuss the diagnostic options and surgical management of exertional anterior compartment syndrome of the leg in this group of patients. METHODS: Data from a series of athletes presenting with exertional leg pain were analysed and categorized according to aetiology. RESULTS: Sixty-six athletes presenting with exertional leg pain in 102 limbs were analysed. Sixteen patients in a first group of 20 patients with a provisional diagnosis of exertional anterior compartment syndrome of the leg underwent a closed fasciotomy with complete resolution of symptoms. A second group of 42 patients were diagnosed as medial tibial stress syndrome and a third group of four patients had confirmed stress fracture of the tibia. CONCLUSION: Exertional leg pain is a common presenting complaint of athletes to sports physicians and physiotherapists. Careful analysis can lead to an accurate diagnosis and commencement of effective treatment. Exertional anterior compartment syndrome can be successfully treated utilizing a closed fasciotomy with a rapid return to sport.
Assuntos
Síndrome do Compartimento Anterior/cirurgia , Traumatismos em Atletas , Adolescente , Adulto , Síndrome do Compartimento Anterior/diagnóstico , Síndrome do Compartimento Anterior/etiologia , Fasciotomia , Feminino , Fraturas de Estresse/diagnóstico , Fraturas de Estresse/terapia , Humanos , Masculino , Esforço Físico , Fraturas da Tíbia/diagnóstico , Fraturas da Tíbia/terapia , Adulto JovemRESUMO
To assess the impact of spleen status on engraftment, and early morbidity and mortality after allogeneic hematopoietic cell transplantation (HCT), we analyzed 9,683 myeloablative allograft recipients from 1990 to 2006; 472 had prior splenectomy (SP), 300 splenic irradiation (SI), 1,471 with splenomegaly (SM), and 7,440 with normal spleen (NS). Median times to neutrophil engraftment (NE) and platelet engraftment (PE) were 15 vs 18 days and 22 vs 24 days for the SP and NS groups, respectively (P<0.001). Hematopoietic recovery at day +100 was not different across all groups, however the odds ratio of days +14 and +21 NE and day +28 PE were 3.26, 2.25 and 1.28 for SP, and 0.56, 0.55, and 0.82 for SM groups compared to NS (P<0.001), respectively. Among patients with SM, use of peripheral blood grafts improved NE at day +21, and CD34+ cell dose >5.7 × 10(6)/kg improved PE at day+28. After adjusting variables by Cox regression, the incidence of GVHD and OS were not different among groups. SM is associated with delayed engraftment, whereas SP prior to HCT facilitates early engraftment without having an impact on survival.
Assuntos
Neoplasias Hematológicas/mortalidade , Transplante de Células-Tronco Hematopoéticas , Baço/patologia , Baço/cirurgia , Esplenectomia , Adolescente , Adulto , Aloenxertos , Intervalo Livre de Doença , Feminino , Seguimentos , Neoplasias Hematológicas/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Taxa de Sobrevida , Fatores de TempoRESUMO
Fracture of the penis is a well-recognized clinical entity. The ideal management has evolved and repair remains largely surgical. We present the etiology and pathophysiology of this condition and outline the therapeutic options.
Assuntos
Doenças do Pênis , Hematoma/diagnóstico por imagem , Hematoma/patologia , Humanos , Masculino , Doenças do Pênis/diagnóstico por imagem , Doenças do Pênis/patologia , Doenças do Pênis/fisiopatologia , Doenças do Pênis/cirurgia , UltrassonografiaRESUMO
Due to the implication of oxidative stress in neurodegenerative disorders we decided to investigate the antioxidant properties of acetylsalicylic acid and acetaminophen either alone or in combination. The thiobarbituric acid assay (TBA) and the nitroblue tetrazolium (NBT) assay were used to investigate quinolinic acid (QA)-induced: lipid peroxidation and superoxide anion generation in the rat hippocampus, in vivo. The study also shows, using cresyl violet staining, the preservation of structural integrity of neuronal cells following treatment with acetylsalicylic acid and acetaminophen in QA-lesioned rat hippocampus. Furthermore the study sought to determine whether these agents have any effect on endogenous (QA) formation. This study shows that acetylsalicylic acid and acetaminophen inhibit QA-induced superoxide anion generation, lipid peroxidation and cell damage, in vivo, in the rat hippocampus. In addition these agents inhibit the enzyme, 3-hydroxyanthranilic acid oxygenase (3-HAO), responsible for the synthesis of endogenous QA.
Assuntos
Acetaminofen/farmacologia , Analgésicos não Narcóticos/farmacologia , Anti-Inflamatórios não Esteroides/farmacologia , Aspirina/farmacologia , Síndromes Neurotóxicas/prevenção & controle , 3-Hidroxiantranilato 3,4-Dioxigenase/metabolismo , Animais , Hipocampo/efeitos dos fármacos , Hipocampo/enzimologia , Hipocampo/patologia , Masculino , Neurônios/metabolismo , Neurônios/patologia , Síndromes Neurotóxicas/patologia , Nitroazul de Tetrazólio , Oxidantes/toxicidade , Oxirredução , Ácido Quinolínico/toxicidade , Ratos , Ratos Wistar , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismoRESUMO
The effects of 1-methyl-4-phenylpyridinium (MPP+) has been extensively researched due to its selective toxicity to dopaminergic neurons. Mitochondrial dysfunction which is common in the etiology of Parkinson's disease (PD), has been widely implicated in MPP+-induced toxicity. MPP+-induced mitochondrial dysfunction is believed to result in the generation of free radicals. This study was therefore performed to assess the effect of MPP+ on mitochondrial function and the ability of MPP+ to generate superoxide free radicals. Furthermore, we assessed the ability of the non-narcotic analgesics, acetaminophen and acetylsalicylic acid to prevent any diliterious effects of the potent neurotoxin, MPP+, on mitochondrial function and superoxide anion generation, in vivo. Acetylsalicylic acid and acetaminophen prevented the MPP+-induced inhibition of the electron transport chain and complex I activity. In addition, acetylsalicylic acid and acetaminophen significantly attenuated the MPP+-induced superoxide anion generation. Furthermore the results provide novel data explaining the ability of these agents to prevent MPP+-induced mitochondrial dysfunction and subsequent reactive oxygen species generation. While these findings suggest the usefulness of non-narcotic analgesics in neuroprotective therapy in neurodegenerative diseases, acetylsalicylic acid appears to be a potential candidate in prophylactic as well as in adjuvant therapy in Parkinson's disease.
Assuntos
1-Metil-4-fenilpiridínio/antagonistas & inibidores , 1-Metil-4-fenilpiridínio/toxicidade , Acetaminofen/farmacologia , Anti-Inflamatórios não Esteroides/farmacologia , Aspirina/farmacologia , Mitocôndrias/efeitos dos fármacos , Oxidantes/metabolismo , Superóxidos/metabolismo , Animais , Transporte de Elétrons/efeitos dos fármacos , Masculino , NADH NADPH Oxirredutases/metabolismo , Neostriado/efeitos dos fármacos , Neostriado/metabolismo , Nitroazul de Tetrazólio , Ratos , Ratos Wistar , Espécies Reativas de OxigênioRESUMO
BACKGROUND: Proteinuria is used as a criterion in the classification system for hypertensive disorders of pregnancy including preeclampsia. The aim of the study was to evaluate the accuracy of dipstick urinalysis in a single voided urine sample and in an aliquot of a 24-hour urine collection in the assessment of proteinuria in hypertensive pregnant women, using the 24-hour urine protein excretion as the gold standard. METHODS: One hundred ninety-eight women who presented with hypertension in pregnancy were recruited at the antenatal clinic at King Edward VIII Hospital in Durban, South Africa, a tertiary referral center. Exclusion criteria included women with eclampsia, urinary tract infection, and chronic renal disease. Routine dipstick urinalysis (Bayer) was performed by midwives for proteinuria, and a 24-hour urine specimen was collected for quantitative protein assessment. A laboratory technician performed urine dipstick test for protein on a mixed aliquot of the 24-hour urine specimen. This result, together with that of the screening dipstick urinalysis, was compared to the 24-hour urine protein excretion. RESULTS: The results of the 198 patients were analyzed, of the total, 72 had preeclampsia. Using a value of = 0.3 g protein excretion per 24 hours (1 + to 4 + on urine dipsticks) as positive, sensitivity, specificity, and predictive values for dipstick urinalysis were calculated. The positive predictive value for dipstick urinalysis ranged from 64.9% (single voided urine sample) to 94.2% (24-hour urine aliquot). The negative predictive value ranged from 75.2% (single voided urine sample) to 84.2% (24-hour urine aliquot). CONCLUSION: Dipstick urinalysis is not very accurate: therefore, all women presenting with hypertension during pregnancy should have a 24-hour urine protein measurement.
Assuntos
Hipertensão Induzida pela Gravidez/urina , Proteinúria/diagnóstico , Urinálise/instrumentação , Adulto , Feminino , Humanos , Gravidez , Complicações na Gravidez , Proteinúria/etiologia , Fitas Reagentes , Sensibilidade e EspecificidadeRESUMO
Using a cyanide model to induce neurotoxic effects in rat brain homogenates, we examined the neuroprotective properties of three H3 antagonists, namely clobenpropit, thioperamide and impentamine, and compared them to aspirin, a known neuroprotective agent. Superoxide anion levels and malondialdehyde concentration were assessed using the nitroblue tetrazolium and lipid peroxidation assays. Clobenpropit and thioperamide significantly reduced superoxide anion generation and lipid peroxidation. Impentamine reduced lipid peroxidation at all concentrations used, but only reduced superoxide anion generation at a concentration of 1 mM. In the lipid peroxidation assay, all the drugs compared favourably to aspirin. This study demonstrates the potential of these agents to be neuroprotective by exerting antioxidant effects.
Assuntos
Encéfalo/efeitos dos fármacos , Agonistas dos Receptores Histamínicos/farmacologia , Peroxidação de Lipídeos/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Síndromes Neurotóxicas/tratamento farmacológico , Superóxidos/antagonistas & inibidores , Animais , Antioxidantes/farmacologia , Aspirina/farmacologia , Encéfalo/metabolismo , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Imidazóis/farmacologia , Técnicas In Vitro , Masculino , Malondialdeído/antagonistas & inibidores , Piperidinas/farmacologia , Cianeto de Potássio/efeitos adversos , Ratos , Ratos Wistar , Receptores Histamínicos H3/efeitos dos fármacos , Tioureia/análogos & derivados , Tioureia/farmacologiaRESUMO
Melatonin, a naturally occurring chemical mediator, although assigned a diverse range of functions, has attracted interest because of its ability to function as a free radical scavenger. Its major hepatic metabolite and photoproduct, 6-hydroxymelatonin (6-OHM), also shares this property. Since singlet oxygen and quinolinic acid (QUIN) are critically involved in the pathology of neurotoxicity, the objective of this study was to investigate the ability of 6-OHM to scavenge singlet oxygen and evaluate its ability to scavenge superoxide anions and reduce QUIN-induced neurotoxicity in the hippocampus in-vivo. The results show that 6-OHM is an efficient inhibitor of singlet oxygen formation as indicated by the rate constants and quantum yields reported for 6-OHM and zinc phthalocyanine (ZnPc), respectively. 6-OHM, appears to reduce QUIN-induced superoxide anion generation in the hippocampus, which provides some evidence of the neuroprotective effects of 6-OHM.
Assuntos
Sequestradores de Radicais Livres , Hipocampo/efeitos dos fármacos , Hipocampo/patologia , Ácido Quinolínico/toxicidade , Animais , Cardiotônicos , Masculino , Melatonina/análogos & derivados , Fármacos Neuroprotetores , Estresse Oxidativo , Ratos , Ratos WistarRESUMO
AIDS-related encephalopathy, including AIDS dementia complex (ADC) and the opportunistic disease, herpes simplex encephalitis (HSE), are postulated to arise due to the release of neurotoxic products, such as quinolinic acid (QUIN), by activated microglial cells in the brain. QUIN causes a cascade of events to occur, which leads to the production of reactive oxygen species (ROS), these being ultimately responsible for oxidative neurotoxicity. The antiherpes antiviral aciclovir has been reported to protect against neuron loss in HSE, but the mechanism for this neuroprotection is unknown. Therefore, this study was conducted to investigate whether aciclovir has the ability to inhibit QUIN-induced lipid peroxidation in rat brain homogenates, after in-vitro and in-vivo exposure to QUIN and aciclovir. The thiobarbituric acid (TBA) assay was the method used to analyse lipid peroxidation. Rat brains were also examined histologically after in-vivo exposure to visually assess whether neuron loss was suppressed. The results show that aciclovir inhibits the QUIN-induced lipid peroxidation, in a dose-dependent manner. Furthermore, aciclovir reduced necrosis of hippocampal neurons and retained the characteristic morphology, integrity and arrangement of these cells. Thus, it appears that aciclovir has neuroprotective properties, which could possibly be useful in the treatment of AIDS-related encephalopathy.
Assuntos
Complexo AIDS Demência/tratamento farmacológico , Complexo AIDS Demência/fisiopatologia , Aciclovir/farmacologia , Antivirais/farmacologia , Peroxidação de Lipídeos/efeitos dos fármacos , Estresse Oxidativo , Ácido Quinolínico/toxicidade , Animais , Encéfalo , Hipocampo/patologia , Masculino , Necrose , Neurônios/patologia , Fármacos Neuroprotetores , Ratos , Ratos Wistar , Espécies Reativas de OxigênioRESUMO
Melatonin, a naturally occurring chemical mediator, although assigned a diverse range of functions, has attracted interest in recent years because of its ability to function as a free radical scavenger. Because of the implications of singlet oxygen in neurotoxicity, the objective of the study was to investigate the ability of melatonin to quench singlet oxygen generated using laser irradiation or lamp photolysis. The results show that melatonin produces radicals upon laser irradiation while the lamp photolysis studies show that melatonin is able to scavenge singlet oxygen produced by naphthalene. While melatonin is a free radical scavenger under biological conditions, it acts as a generator of singlet oxygen and or radicals (as PhiDelta is 1.41) when irradiated with laser light, implying that it has the potential to be used in photodynamic therapy in the destruction of tumors.